Benign familial macrocephaly: report of a family and review of the literature.

Five members in two generations of one family were found to have occipitofrontal head circumferences more than 2 SD above the mean. All five had normal intelligence and neurological examinations. Three of the five had ventricular dilatation by A-mode echoencephalography. The inheritance pattern of macrocephaly in this family appears to be autosomal dominant with incomplete penetrance. Possible causes of the macrocephaly in this family are discussed and the reported cases of macrocephaly with normal intelligence and no neurological deficits are reviewed.